bpd: add mixramp commands

These are a more sophisticated version of crossfade so we're free to
ignore them, at least for now. We now track the values of the two
settings, and show them in the status output. Like MPD, we suppress the
mixrampdb value if it's set to nan, which is how it signals that the
feature should be turned off.

beetsplug/bpd/__init__.py

@@ -25,6 +25,7 @@ from string import Template
 import traceback
 import random
 import time
+import math
 
 import beets
 from beets.plugins import BeetsPlugin
@@ -174,6 +175,8 @@ class BaseServer(object):
         self.repeat = False
         self.volume = VOLUME_MAX
         self.crossfade = 0
+        self.mixrampdb = 0.0
+        self.mixrampdelay = float('nan')
         self.playlist = []
         self.playlist_version = 0
         self.current_index = -1
@@ -307,8 +310,11 @@ class BaseServer(object):
             u'random: ' + six.text_type(int(self.random)),
             u'playlist: ' + six.text_type(self.playlist_version),
             u'playlistlength: ' + six.text_type(len(self.playlist)),
+            u'mixrampdb: ' + six.text_type(self.mixrampdb),
         )
 
+        if not math.isnan(self.mixrampdelay):
+            yield u'mixrampdelay: ' + six.text_type(self.mixrampdelay)
         if self.crossfade > 0:
             yield u'xfade: ' + six.text_type(self.crossfade)
 
@@ -358,6 +364,22 @@ class BaseServer(object):
         self._log.warning(u'crossfade is not implemented in bpd')
         self.crossfade = crossfade
 
+    def cmd_mixrampdb(self, conn, db):
+        """Set the mixramp normalised max volume in dB."""
+        db = cast_arg(float, db)
+        if db > 0:
+            raise BPDError(ERROR_ARG, u'mixrampdb time must be negative')
+        self._log.warning('mixramp is not implemented in bpd')
+        self.mixrampdb = db
+
+    def cmd_mixrampdelay(self, conn, delay):
+        """Set the mixramp delay in seconds."""
+        delay = cast_arg(float, delay)
+        if delay < 0:
+            raise BPDError(ERROR_ARG, u'mixrampdelay time must be nonnegative')
+        self._log.warning('mixramp is not implemented in bpd')
+        self.mixrampdelay = delay
+
     def cmd_clear(self, conn):
         """Clear the playlist."""
         self.playlist = []

test/test_player.py

@@ -361,7 +361,7 @@ class BPDQueryTest(BPDTestHelper):
 
 class BPDPlaybackTest(BPDTestHelper):
     test_implements_playback = implements({
-            'consume', 'mixrampd', 'mixrampdelay', 'random',
+            'consume', 'random',
             'repeat', 'setvol', 'single', 'replay_gain_mode',
             'replay_gain_status', 'volume',
             }, expectedFailure=True)
@@ -379,6 +379,26 @@ class BPDPlaybackTest(BPDTestHelper):
         self.assertNotIn('xfade', responses[0].data)
         self.assertAlmostEqual(123, int(responses[2].data['xfade']))
 
+    def test_cmd_mixrampdb(self):
+        with self.run_bpd() as client:
+            responses = client.send_commands(
+                    ('mixrampdb', '-17'),
+                    ('status',))
+        self._assert_ok(*responses)
+        self.assertAlmostEqual(-17, float(responses[1].data['mixrampdb']))
+
+    def test_cmd_mixrampdelay(self):
+        with self.run_bpd() as client:
+            responses = client.send_commands(
+                    ('mixrampdelay', '2'),
+                    ('status',),
+                    ('mixrampdelay', 'nan'),
+                    ('status',),
+                    ('mixrampdelay', '-2'))
+        self._assert_failed(responses, bpd.ERROR_ARG, pos=4)
+        self.assertAlmostEqual(2, float(responses[1].data['mixrampdelay']))
+        self.assertNotIn('mixrampdelay', responses[3].data)
+
 
 class BPDControlTest(BPDTestHelper):
     test_implements_control = implements({